As a beginner(in GdxLib+Android), i found that for rendering particular screen, we can render that using both ways then when to use specific ones? & What is the best option for Updating the smaller part/region of the screen?
ShapeRenderer isn't efficient and shouldn't be used intensively.
Renders points, lines, rectangles, filled rectangles and boxes. This class is not meant to be used for performance sensitive applications but more oriented towards debugging.
That being said, I asked for opinions on its real impact here, but since I've got no answer yet, I decided to give a try. It's working nice so far but if you can use a texture, I'd say to go with that. (I'm not using a texture because I'm writing a small library and don't want to include non code).